1. Technical Field
This invention relates in general to electronic circuits and, more particularly, to digital signal processors.
2. Description of the Related Art
The global market for digital signal processors (DSPs) has grown at a compounded rate of more than 30 percent per year since 1988. In fact, the market for DSPs is actually developing along a faster track than the one the microprocessor followed in the 1980s and 1990s. In part, this fast-track growth is driven by the fact that digital signal processors target a broader range of diverse end use products than microprocessors: not just personal computers, but also telecommunication devices, consumer electronics, office equipment, industrial controls and automotive components.
The success of DSPs in the marketplace is largely due to their ability to crunch vast quantities of numbers, while racing against an incredibly demanding clock. Digital signal processors are much faster (often 10 times faster or more) than general-purpose microprocessors, which makes digital signal processors particularly well-suited to handle the demands of processing information from different parts of our world by working in real time.
One shortcoming of DSPs is that their functionality is limited by the amount of their internal memory. While improvement in semiconductor fabrication have increased the amount of memory which can be placed on a DSP, the complexity of the applications has increased the need for instruction and data memory even more so.
In the future, applications executed by DSPs will be more complex and will likely involve multiprocessing by multiple DSPs in a single system. DSPs will evolve to support multiple, concurrent applications, some of which will not be dedicated to a specific DSP platform, but will be loaded from a global network such as the Internet. These DSP platforms will require a RTOS (real time operating system) to schedule multiple applications and to support memory management to share and protect memory access efficiently between applications and operating system kernels.
Accordingly, a need has arisen for a DSP capable of memory management, including the accessing large amounts of memory.
In the present invention, a digital signal processor is provided which includes an interface for connecting to an external memory, a processing core and a memory management unit coupled to the interface and the processing core. The memory management unit receives virtual addresses from the processing core and translates the addresses to physical addresses associated with said external memory.
The present invention provides significant advantages over the prior art. Virtual addressing allows the DSP to work with a large address space on a local memory and an external memory which can be shared with other processing units.